The 6-foot-11 Opelka, ranked No. 228, hit 17 aces. With two victories this week, he has doubled his win total for all of 2017.

No. 6-seeded John Isner hit 30 aces and swept all 18 of his service games but lost to Peter Gojowczyk Open, 7-6 (3), 6-7 (4), 7-6 (5). Isner won only nine points on Gojowczyk's first serve and fell to 1-4 this year.